Heart disease continues to diminish the quality and claim the lives of many American despite increasing evidence that the consequences of cardiovascular disease can be reduced through modification of health and risk behaviors, even among older adult patients. The role of the patients' support network in facilitating (or hindering) behavior change has received increasing attention in the empirical literature. Thus, this study of 100 heart disease patients and their spouses explores individual perceptions of supportive, controlling, and undermining exchanges by the other in response to recommendations for adoption and maintenance of exercise activity. In light of the known benefits of health promoting behavior such as exercise in forestalling the disablement of heart disease, this study focuses on the transtheoretical model of individual stages and processes of exercise behavior change. In addition, the proposed project explores exercise behavior change within the larger context of the patient's family. In that marital partners importantly influence patient adjustment to illness, this study investigates individual behavior change of each partner. It is proposed that the shared perspective on behavior change afforded by similarity in stage and corresponding processes of change will enhance partners' coping assistance in adopting health-sustaining exercise behavior through more supportive, fewer controlling and fewer undermining exchanges regarding exercise activity. The aims of the proposed project are threefold. First, this study examines the present stage and correspondent processes of change in the exercise behavior of patients enrolled in a cardiac rehabilitation program and that of their spouses. Second, it investigates individual perceptions of patients and of spouses regarding their supportive, controlling, and undermining exchanges pertaining to engagement in exercise behavior. Last, it tests the relationship between individual stage and corresponding processes of change with perceptions of supportive, controlling, and undermining exchanges of the partner.